feat: add image zoom options (#984)

app/assets/javascripts/Components/Files/ImagePreview.tsx

@@ -0,0 +1,64 @@
+import { IconType } from '@standardnotes/snjs'
+import { FunctionComponent } from 'preact'
+import { useEffect, useRef, useState } from 'preact/hooks'
+import { IconButton } from '../Button/IconButton'
+
+type Props = {
+  objectUrl: string
+}
+
+export const ImagePreview: FunctionComponent<Props> = ({ objectUrl }) => {
+  const initialImgHeightRef = useRef<number>()
+
+  const [imageZoomPercent, setImageZoomPercent] = useState(100)
+  const [imageHeight, setImageHeight] = useState(initialImgHeightRef.current)
+
+  useEffect(() => {
+    if (initialImgHeightRef.current) {
+      setImageHeight(imageZoomPercent * (initialImgHeightRef.current / 100))
+    }
+  }, [imageZoomPercent])
+
+  return (
+    <div className="flex items-center justify-center w-full h-full overflow-auto">
+      <img
+        src={objectUrl}
+        height={imageHeight}
+        ref={(imgElement) => {
+          if (!initialImgHeightRef.current) {
+            initialImgHeightRef.current = imgElement?.height
+          }
+        }}
+      />
+      <div className="flex items-center absolute bottom-6 py-1 px-3 bg-default border-1 border-solid border-main rounded">
+        <span className="mr-1.5">Zoom:</span>
+        <IconButton
+          className="hover:bg-contrast p-1 rounded"
+          icon="add"
+          title="Zoom In"
+          focusable={true}
+          onClick={() => {
+            setImageZoomPercent((percent) => percent + 10)
+          }}
+        />
+        <span className="mx-2">{imageZoomPercent}%</span>
+        <IconButton
+          className="hover:bg-contrast p-1 rounded"
+          icon={'subtract' as IconType}
+          title="Zoom Out"
+          focusable={true}
+          onClick={() => {
+            setImageZoomPercent((percent) => {
+              const newPercent = percent - 10
+              if (newPercent >= 10) {
+                return newPercent
+              } else {
+                return percent
+              }
+            })
+          }}
+        />
+      </div>
+    </div>
+  )
+}